I got the Basic Brewing DVD, and on it they suggest soaking bottles in warm water for a while, then peeling the labels off as best you can, then using a stainless steel scouring pad to take off the rest of the gunk. I tried it, and it works as advertised. I used a large ice chest in leiu of a large sink, and found the water gunked up terribly - which means I had to change it out between bottle batches, and had to dump it out in the yard for fear I'd clog my drains inside. The scouring pad also gunked up 'til it was unusable.

Next time around, I had seen here on HBT where an overnight soak in warm to hot water spiked with OxyClean will cause the labels to remove themselves. So I gave it a shot, and it also worked as advertised. The labels literally floated off all by themselves, and I was left with nice neat waste water. Also involved no scouring pad whatever. A distinct improvement!

On de-label session no. 3 -- each of these sessions invloved about two cases worth of bottles -- I used too-tepid water and/or not enough OxyClean, evidently, as I was back to a lot of what I describe in the first paragraph, and that's a lotta work...

On session no. 4, I made sure the water was plenty hot, nearly too much to stand sticking an arm in, but not enough to cause scalding, and added half a scoop of OxyClean, and was back to second paragraph results. De-labeling is as painless as it's ever gonna get using this method. The ice chest keeps the water nice and hot for a couple days, too.

some just are more adhesive than others I guess.
I just cleaned a batch of various brands; Sam Adams, Konig Ludwig, Dos Equis, Corona and Smithwick's.

Put about 60 in a large tub filled with warm water and oxyclean. Let it sit over night. The Sam Adam's fell off the easiest. I basically just pulled the bottles out and the labels were sitting in the water. Corona obviously are the hardest since I think they paint theirs on. I think I read a post from Revvy about how he let them sit in water for about a week or more and found they started to come off.

Dos Equis caused me some problems at first. After 24 hours of soaking they peeled off partially but left a lot of their backing to the bottle still. I found if I just removed the front part after a 24 hour soak...returned them to the water for another 24 hours, then scrubbed them with a bottle brush, the residue came right off.

I soaked the bottles in hot water overnight, the next day peeled off main label some were cleaner than others then I placed bottles back in water for another day and then took paper towels and sprayed windex on them and it seems to eat the rest of the sticky right off and you have a clean bottle.

I did my first batch (60 bottles) in a large container with approximately 12.5 gallons of hot water and I think I used way too much oxyclean (4 whole scoops). After a couple laps in the dishwasher to clean out the bottles I sill think that I can taste some off flavor from the the oxyclean (slight burning?).

Yes some are worse than others. Also, I just use hot water and let them soak and they nearly all come off after an hour. Just a bit of scrubbing with green pads to remove residue. Have not tried oxy-clean yet.

Guinness bottles have a peelable plastic label and the shape is sexy, so you can use those and not have to peel labels either. The widget that is inside comes out with needlenose pliers easy enough too.